I saw a bird in the park.

He is researching about a new energy source.

He is conducting research on a new energy source.

He is known as a person with learning.

I saw a bird in the park.

Mr. Tori is my neighbor.

Birds have feathers and wings.

He couldn't say anything about issues outside of his field of expertise.

There are many different specialty stores in this town.

He is a specialist fool, with no interest in anything outside his field.